The acrosome is synthesized and assembled, at least in part, by the Golgi apparatus of the spermatocyte. Both the acrosome and the enclosed enzymatic systems, as well as portions of the sperm plasma membrane, may be altered or regulated by the male ducts (epididymis, vas deferens, etc.) during maturation or by the accessory gland secretions during and immediately following ejaculation. Our interest is in how these secretory processes occur and are regulated to affect fertilization capacity. Such information seems imperative to development of new fertility control methods in the male. Research goals for the coming year include: determination of regulatory roles for components of the cell surface in spermatogenesis, capacitation, and the acrosome reaction and to examine the role of the Golgi apparatus in biosynthesis of the components. Studies will utilize newly developed in vivo systems to obtain egg-sperm complexes having the acrosome reaction, in vitro assays for activation of RNA polymerase, and other procedures unique to the project.